Sewing machine



Aug. 28, 1956 Filed Jan. 2, 1953 R. SCHUBERT SEWING MACHINE 2 Sheets-Sheet 1 INVENTOR BY i mms Aug. 28, 1956 R. SCHUBERT SEWING MACHINE Filed Jan. 2, 1953 2 Sheets-Sheet 2 INVENTOR E00 04 F Sax/02527 ATTORNEYS:

United States Patent SEWING MACHINE Rudolf Schubert, Diedorf, near Augsburg, Germany, as-

signor to Hillier & Co. K. G., Augsburg, Germany, a corporation of Germany Application January 2, 1953, Serial No. 329,166

Claims priority, application Germany January 16, 1952 Claims. (Cl. 1112-20) This invention relates to sewing machines and has particular reference to overlook sewing machines of the type having feed cups for feeding the work to and past the stitching mechanism and coupling means for adjusting the feed.

Hitherto, in sewing machines of the kind referred to, the coupling means had to be locked in their actually adjusted position to resist the reaction forces exerted upon the coupling means by the machine. Therefore, the size of stitch had to be set while the machine was not sewing.

It is an object of the present invention to provide coupling means permitting adjustment of the size of stitch Without interruption of the sewing operation, so as to permit, for instance, sewing of the seam of a stocking with variable length of the stitch at the various portions of the leg of the stocking.

Another object of the invention is to provide infinitely variable coupling means permitting continuous variation of the length of the stitch.

A still further object of the invention is to provide a coupling mechanism which is of small size and can be accommodated in the machine so as to be easily accessible.

Still another object of the invention is to provide a stitch regulator which can be operated by the knee of the operator.

With these and further objects in view, according to the present invention the coupling mechanism is constructed in the form of a self-locking mechanism which can be adjusted during the sewing operation of the machine.

Various coupling mechanisms can be used to this end, but according to a preferred form of the invention the clutch mechanism consists of a combination of two oneway clutches acting in opposite directions and comprising means for rotative displacement of the driven member in relation to the driving member, whereby the efiective stroke of a connecting rod connected with the driven member can be varied with constant angle of oscillation of the driving member.

Preferably the clutch mechanism is coupled with a lever which can be operated by the knee of the operator against spring action through a regulating range limited by a zero stop and/or by an adjustable stop defining a specified length of the stitch.

According to a still further feature of the invention the knee-operated lever is linked to the draw rod serving to swing the carrier of the outer feed cup, said draw rod being rotatable and carrying on its upper part a pivoted arm for connection to the adjustable coupling device. In this case, no additional element is required for mounting the knee-operated lever and no additional member vertically traversing the frame of the machine is required.

Other and further objects, features and advantages of the invention will be pointed out hereinafter and appear in the appended claims forming part of the application.

In the accompanying drawing a now preferred embodiice ment of the invention is shown by way of illustration and not by way of limitation.

Fig. 1 is an axial section of the feed mechanism,

Fig. 1-A is an enlarged view of the structure in Fig. 1 which surrounds the shaft 14,

Fig. 2 is a plan View thereof, in a fragmentary section on line lIII of Fig. 1, on a larger scale,

Fig. 3 is an elevation showing the operation by a kneeoperated lever and Fig. 4 is a plan view thereof.

Similar reference numerals denote similar parts in the different views.

Referring now to the drawings in greater detail, it will be seen that the sewing machine comprises a machine frame 1 carrying the inner feed cup 2 and the outer feed cup 3 Whose carrier 4 is fulcrumed on a pivot 6 mounted in a bearing bracket 5. Both feed cups are driven from a common shaft 7 through spur-wheels (not shown). The shaft 7 is intermittently driven through a one-way clutch 8, 9, whose clamp rollers 10 act to couple the driving member 9 with the driven member 8 in one direction of rotation only while freewheeling in an opposite direction of rotation. The oscillating drive of the driving member 9 is effected by a connecting rod 11 Whose opposite end is jointed at 12 to a lever 13 which is connected through a shaft 14 with the driven member 15 of a clutch which member 15- is coupled with its driving member 17 through a clamp roller 16 in one direction of rotation and through a clamp roller 16 in an opposite direction of rotation. The driving member 17 in turn is oscillated through a rod 18 by the crank 19 of the main shaft 20 of the machine, member 17 being mounted coaxially to shaft 14, by a sleeve-shaped extension 22, in the bearing bracket 21.

Rotative displacement of the driven member 15 is possible in relation to the driving member 17 while maintaining the twoway ratchet connection, as will be hereinafter described, whereby the effective stroke of the connecting rod 11 which is connected to the driving member 9 of the one-way feed cup advancing clutch is changed.

The relative rotative displacement of members 15 and 17 is eifected through a pair of pins 23 whose lower free ends are movably disposed within a recess 23 in the driven member 15 and which recess is concentric to the axes of members 15 and 17 and whose opposite ends open into the roller-receiving recesses in the member 15. The upper ends of pins 23 are secured to a ring 24 which is secured to shaft 25, the upper end of which carries a setting lever 26 whose position is indicated by a pointer on a scale on the machine frame. A spring 38 later referred to serves to hold the setting lever against a stop, later referred to.

In the position shown in Fig. 2 the annular collar of the driving member 17 acts to take with it the driven member 15, i. e. through roller 16 in an anti-clockwise direction and through roller 16' in a clockwise direction, without engagement of the rollers 16, 16' with the pins 23. However, when the pins 23 are displaced in their angular position by operation of shaft 25, for instance, in a clockwise direction, through the ring 24, which is possible owing to the recess provided in the driven member 15, then the roller 16 on its next oscillating stroke in an anti-clockwise direction will strike against the pin 23 next to it, whereby the frictional coupling between the driving ring 17 and the driven ring 15 is interrupted and on further swinging of the driving ring 17 with its constant stroke defined by the crank 19 a relative displacement will take place between the parts 17 and 15. In case of a displacement of the pins 23 in an anticlockwise direction the same process takes place between the roller 16' and the pin 23 next to this roller.

In the construction shown in Figs. 3 and 4 the setting lever 26 is limited as to its range of adjustment between stops 27 and 28 limiting the maximum and minimum feed. The stops 27, 28 are mounted on carriers 29 which are swingable and can be clamped in position by screws 30. The setting lever 26 has a second arm 31 to which is connected, through a ball joint 32, a link 33 which in turn is connected through a ball joint 32' with a lever 34 mounted on the upper end of a rod 35 which is provided, below the table 36 of the machine, with a knee-operated lever 37 which under action of a helical tension spring 38 tends to force the setting lever 26 towards the stop 27. By operation of the lever 37 against action of the spring 38in a clockwise direction in the example shown in Fig. 4-:the setting lever 26 is swung away from its stop 27 up to the stop 28, whereby the feed is changed accordingly.

Fastened to the lower end of the draw rod 35 is a foot-operated pull wire 39 by which the rod 35 can be drawn downwards, so that its flange 40 through an arm 41 swings the carrier 4 about its pivot 6 for swinging the outer feed cup 3 away from the inner feed cup 2. The compression spring 42 acting on the lower face of the arm 41 provided on the carrier 4 tends to urge the outer feed cup 3 against the inner feed cup 2. The spring 42 is supported on an abutment 44 of the machine frame which can be adjusted and is accessible through a longitudinal cut-out 43 thereof.

The invention may be more concisely stated as follows: The cooperating material engaging feed cups 2 and 3 are as in usual practice intermittently driven by a shaft 7 and which shaft in common with usual practice is stepped by a one-way oscillatory clutch embodying a driven member 8 and a driving member 9. The driving member 9 is connected to the driven member of a two-way oscillatory clutch which includes also a driving member 17 which is connected to a source of power through a connecting rod 18 and a crank 19. In other words, the feed cup advancing shaft is operated by a one-way drive friction clutch which in turn is driven by a two-way drive friction clutch.

The two-way drive friction clutch is of the oscillatory type and embodies cooperating driving and driven members the former of which is given a stroke of constant amplitude at all times, whereas the driven member is variable in its amplitude as occasioned by adjusting means herein disclosedas a pair of pins adjustable about the axis of the driving and driven members and adapted to interrupt the driving connection between said members to thereby vary the effective amplitude of the driven member of the feed cup advancing clutch.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention it will be understood by those skilled in the art after understanding the invention that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

I claim:

1. In a sewing machine, a frame, a shaft supported in said frame, a two-way oscillatory friction clutch including a member fixed to said shaft and a power driven member oscillatable about said shaft through predetermined angles on opposite sides of a fixed point, a feed cup operating shaft supported in said frame, a one-way oscillatory friction clutch connected to said last shaft, a driving connection between said last clutch and the first member of said first clutch, and manually adjustable means supported by said frame for varying the angular range of movement of said first member with respect to said second member whereby to vary the operative angular range of said feed cup operating shaft.

2. In a cup feed sewing machine, a frame, a vertical shaft oscillatably supported in said frame, a second vertical shaft oscillatably supported in said frame, cooperating feed cups driven by said second shaft, a one-Way ball friction clutch including a driven member secured to said second shaft and a driving member surrounding same, a two-way ball friction clutch including a driven member secured to said first shaft and a driving member surrounding same, a power driven connection to said last driving member for imparting oscillatory movement thereto about said first shaft through predetermined angular ranges of movement, a drive connection between the first driven member and the second driving member, and manually operable means supported by the frame for varying the angular range of movement of the driven member of the first clutch with respect to the driving member thereof.

3. A structure according to claim 2, wherein said twoway ball friction clutch comprises a pair of spring pressed balls interposed between the driven and driving members thereof and wherein said manually operable means comprises a member rotatable about said first shaft, and a pin depending from said member in parallel relation to said first shaft with a portion thereof disposed within the path of movement of one of said balls for limiting the movement thereof as occasioned by relative movement between said driven and driving members whereby movement of the first of said members is interrupted.

4. A structure according to claim 3, wherein said pin-carrying member is supported by the lower end ofa shaft supported by said frame in coaxial relation to said first shaft, and means for imparting rotation to said last shaft.

5. A structure according to claim 4, wherein said means comprises a lever fixed to the upper end of said last shaft, adjustable stopsat oppositesides of said lever, and knee operable means connected to said lever for movement thereof between said stops.

References Cited in the file of this patent UNITED STATES PATENTS.

620,135 Howe Feb. 28, 1899 939,548 Prazak Nov. 9, 1909 1,404,357 Flanagan Jan. 24, 1922 1,518,545 Onderdonk Dec. 9, 1924 2,681,718 Stoner June 22, 1954 

